100% Free

No Scanner Needed

Carly logo
Prices

anna_koch4

Phaeton Key Fob Failure: Central Locking Issues Fixed

My 2004 Phaeton diesel started acting up with keyless access issues. The fob battery warning hasnt appeared yet, but the electronic key wont unlock or lock the car reliably anymore. The central locking system sometimes works, other times not at all. Already checked the error memory and found stored errors. Has anyone experienced similar symptoms? Looking for feedback from those who got this fixed, what was the actual problem and how was it resolved? Particularly interested in workshop diagnoses and repair solutions that worked.

Summary of the thread

The 2004 Phaeton experienced keyless access issues with the electronic key failing to reliably lock or unlock the car. Despite no battery warning, the problem was traced to a low voltage in the key fob battery. Replacing the battery resolved the central locking issues, with error codes clearing automatically. The solution was straightforward and cost-effective, highlighting the importance of checking the key fob battery before pursuing more complex diagnostics.

Did this summary help you solve your problem?

4 comment(s)

jannikfuchs19

Had nearly identical issues with my 2006 VW Touareg V10 TDI. As someone with intermediate car maintenance experience, I recognized similar symptoms, unreliable central locking and key fob issues. Even without the low voltage warning, a weak battery in the electronic key was causing intermittent operation. The car key would work sometimes, then completely fail other times. The workshop confirmed the dead key fob battery was the culprit, though the warning hadnt triggered yet. Quick fix: had the key fob battery replaced at the workshop, total cost 37€ including diagnostic check. The central locking system worked flawlessly after that. To help troubleshoot your specific case: What exact error codes are stored? Does the key work better when held very close to the door handle? Have you noticed any other electrical issues? Worth checking the key fob battery first, its often overlooked but causes these exact symptoms. Could save you time and money before diving into more complex electrical diagnostics.

anna_koch4 (community.author)

Just had my regular service at 105811km. After the battery replacement in the electronic key, everything works perfectly again. The error codes cleared automatically. Holding the key near the door handle did improve function temporarily, confirming the low voltage issue in the fob battery. No other electrical problems noticed since the fix. Total repair cost was 35€ including key battery diagnostics.

jannikfuchs19

Thanks for confirming the auto key diagnosis worked out. Good to hear the battery replacement solved the keyless access issues, matches exactly what I experienced with my Touareg. The symptoms perfectly aligned with a classic low battery scenario in the key fob, especially how holding it closer to the door handle temporarily improved function. This is a telltale sign of low voltage in the car key transmitter. The automatic error code clearance after battery replacement is typical for these central locking issues. In my case, the error memory also cleared itself once proper voltage was restored to the key fob system. Your repair cost of 35€ was actually slightly better than what I paid (37€) for essentially the same fix. It shows these key fob battery replacements are fairly standardized services. Just a heads up, might be worth noting when you had this battery replaced so you can anticipate the next replacement interval. My key fob batteries typically last 3-4 years before showing these symptoms again.

anna_koch4 (community.author)

Thanks for the input. Really glad I checked here before spending more on complex diagnostics. After getting the fob battery replaced during my 105811km service, the electronic key works perfectly again. The proximity test near the door handle confirmed what you all suggested about the key battery being the culprit. Central locking now works consistently and all error codes cleared on their own. Total cost was just 35€ including diagnostics, definitely worth fixing early before it completely failed. Will mark my calendar to check the key battery again in about 3-4 years based on the typical lifespan mentioned. Nice to have such a straightforward solution to what seemed like a major keyless access problem.

rmh_community_comment_box_header

community_crosslink_scanner_headline

community_crosslink_scanner_intro

community_crosslink_scanner_title

community_crosslink_scanner_price

community_crosslink_rmh_headline

community_crosslink_rmh_intro

community_crosslink_rmh_title

community_crosslink_rmh_subtitle

community_crosslink_rmh_brand

VW

community_crosslink_rmh_model

PHAETON